Stage 4 diagnosis and no follow up?

Hello, My elderly mother was last week diagnosed with advance large cancer in small bowel which has spread to her lungs.  At the moment she is feeling very well apart from tummy rumbles and backache and occassional tummy ache.  She was admitted to A&E because of sever stomach pains and discharged a few days later and told there is nothing they can do. So she has no treatment plan or follow up appointments, just a 'just in case' pack!  She also has dementia so has no memory of going into hospital.  Any information or advice on how best I can support her would be really helpful.